Initial commit of OpenSPARC T2 architecture model.

[OpenSPARC-T2-SAM] / sam-t2 / devtools / amd64 / lib / perl5 / 5.8.8 / i86pc-solaris-64-ld / Encode / Alias.pm

package Encode::Alias;
use strict;
no warnings 'redefine';
use Encode;
our $VERSION = do { my @r = (q$Revision: 2.4 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
sub DEBUG () { 0 }

use base qw(Exporter);

# Public, encouraged API is exported by default

our @EXPORT = 
   qw (
       define_alias
       find_alias
       );

our @Alias;  # ordered matching list
our %Alias;  # cached known aliases

sub find_alias{
   my $class = shift;
   my $find = shift;
   unless (exists $Alias{$find}) {
       $Alias{$find} = undef; # Recursion guard
       for (my $i=0; $i < @Alias; $i += 2){
           my $alias = $Alias[$i];
           my $val   = $Alias[$i+1];
           my $new;
           if (ref($alias) eq 'Regexp' && $find =~ $alias){
               DEBUG and warn "eval $val";
               $new = eval $val;
               DEBUG and $@ and warn "$val, $@";
           }elsif (ref($alias) eq 'CODE'){
               DEBUG and warn "$alias", "->", "($find)";
               $new = $alias->($find);
           }elsif (lc($find) eq lc($alias)){
               $new = $val;
           }
           if (defined($new)){
               next if $new eq $find; # avoid (direct) recursion on bugs
               DEBUG and warn "$alias, $new";
               my $enc = (ref($new)) ? $new : Encode::find_encoding($new);
               if ($enc){
                   $Alias{$find} = $enc;
                   last;
               }
           }
       }
       # case insensitive search when canonical is not in all lowercase
       # RT ticket #7835
       unless ($Alias{$find}){
           my $lcfind = lc($find);
           for my $name (keys %Encode::Encoding, keys %Encode::ExtModule){
               $lcfind eq lc($name) or next;
               $Alias{$find} =  Encode::find_encoding($name);
               DEBUG and warn "$find => $name";
           }
       }
   }
   if (DEBUG){
       my $name;
       if (my $e = $Alias{$find}){
           $name = $e->name;
       }else{
           $name = "";
       }
       warn "find_alias($class, $find)->name = $name";
   }
   return $Alias{$find};
}

sub define_alias{
   while (@_){
       my ($alias,$name) = splice(@_,0,2);
       unshift(@Alias, $alias => $name);   # newer one has precedence
       if (ref($alias)){
           # clear %Alias cache to allow overrides
           my @a = keys %Alias;
           for my $k (@a){
               if (ref($alias) eq 'Regexp' && $k =~ $alias){
                   DEBUG and warn "delete \$Alias\{$k\}";
                   delete $Alias{$k};
               }
               elsif (ref($alias) eq 'CODE'){
                   DEBUG and warn "delete \$Alias\{$k\}";
                   delete $Alias{$alias->($name)};
               }
           }
       }else{
           DEBUG and warn "delete \$Alias\{$alias\}";
           delete $Alias{$alias};
       }
   }
}

# Allow latin-1 style names as well
# 0  1  2  3  4  5   6   7   8   9  10
our @Latin2iso = ( 0, 1, 2, 3, 4, 9, 10, 13, 14, 15, 16 );
# Allow winlatin1 style names as well
our %Winlatin2cp   = (
                     'latin1'     => 1252,
                     'latin2'     => 1250,
                     'cyrillic'   => 1251,
                     'greek'      => 1253,
                     'turkish'    => 1254,
                     'hebrew'     => 1255,
                     'arabic'     => 1256,
                     'baltic'     => 1257,
                     'vietnamese' => 1258,
                    );

init_aliases();

sub undef_aliases{
   @Alias = ();
   %Alias = ();
}

sub init_aliases
{
   undef_aliases();
   # Try all-lower-case version should all else fails
   define_alias( qr/^(.*)$/ => '"\L$1"' );

   # UTF/UCS stuff
   define_alias( qr/^UTF-?7$/i           => '"UTF-7"');
   define_alias( qr/^UCS-?2-?LE$/i       => '"UCS-2LE"' );
   define_alias( qr/^UCS-?2-?(BE)?$/i    => '"UCS-2BE"',
                 qr/^UCS-?4-?(BE|LE)?$/i => 'uc("UTF-32$1")',
                 qr/^iso-10646-1$/i      => '"UCS-2BE"' );
   define_alias( qr/^UTF-?(16|32)-?BE$/i   => '"UTF-$1BE"',
                 qr/^UTF-?(16|32)-?LE$/i   => '"UTF-$1LE"',
                 qr/^UTF-?(16|32)$/i       => '"UTF-$1"',
               );
   # ASCII
   define_alias(qr/^(?:US-?)ascii$/i => '"ascii"');
   define_alias('C' => 'ascii');
   define_alias(qr/\bISO[-_]?646[-_]?US$/i => '"ascii"');
   # Allow variants of iso-8859-1 etc.
   define_alias( qr/\biso[-_]?(\d+)[-_](\d+)$/i => '"iso-$1-$2"' );

   # At least HP-UX has these.
   define_alias( qr/\biso8859(\d+)$/i => '"iso-8859-$1"' );

   # More HP stuff.
   define_alias( qr/\b(?:hp-)?(arabic|greek|hebrew|kana|roman|thai|turkish)8$/i => '"${1}8"' );

   # The Official name of ASCII.
   define_alias( qr/\bANSI[-_]?X3\.4[-_]?1968$/i => '"ascii"' );

   # This is a font issue, not an encoding issue.
   # (The currency symbol of the Latin 1 upper half
   #  has been redefined as the euro symbol.)
   define_alias( qr/^(.+)\@euro$/i => '"$1"' );

   define_alias( qr/\b(?:iso[-_]?)?latin[-_]?(\d+)$/i 
                 => 'defined $Encode::Alias::Latin2iso[$1] ? "iso-8859-$Encode::Alias::Latin2iso[$1]" : undef' );

   define_alias( qr/\bwin(latin[12]|cyrillic|baltic|greek|turkish|
                        hebrew|arabic|baltic|vietnamese)$/ix => 
                 '"cp" . $Encode::Alias::Winlatin2cp{lc($1)}' );

   # Common names for non-latin preferred MIME names
   define_alias( 'ascii'    => 'US-ascii',
                 'cyrillic' => 'iso-8859-5',
                 'arabic'   => 'iso-8859-6',
                 'greek'    => 'iso-8859-7',
                 'hebrew'   => 'iso-8859-8',
                 'thai'     => 'iso-8859-11',
                 'tis620'   => 'iso-8859-11',
                 );

   # At least AIX has IBM-NNN (surprisingly...) instead of cpNNN.
   # And Microsoft has their own naming (again, surprisingly).
   # And windows-* is registered in IANA! 
   define_alias( qr/\b(?:cp|ibm|ms|windows)[-_ ]?(\d{2,4})$/i => '"cp$1"');

   # Sometimes seen with a leading zero.
   # define_alias( qr/\bcp037\b/i => '"cp37"');

   # Mac Mappings
   # predefined in *.ucm; unneeded
   # define_alias( qr/\bmacIcelandic$/i => '"macIceland"');
   define_alias( qr/^mac_(.*)$/i => '"mac$1"');
   # Ououououou. gone.  They are differente!
   # define_alias( qr/\bmacRomanian$/i => '"macRumanian"');
 
   # Standardize on the dashed versions.
   define_alias( qr/\bkoi8[\s\-_]*([ru])$/i => '"koi8-$1"' );

   unless ($Encode::ON_EBCDIC){
       # for Encode::CN
       define_alias( qr/\beuc.*cn$/i        => '"euc-cn"' );
       define_alias( qr/\bcn.*euc$/i        => '"euc-cn"' );
       # define_alias( qr/\bGB[- ]?(\d+)$/i => '"euc-cn"' )
       # CP936 doesn't have vendor-addon for GBK, so they're identical.
       define_alias( qr/^gbk$/i => '"cp936"');
       # This fixes gb2312 vs. euc-cn confusion, practically
       define_alias( qr/\bGB[-_ ]?2312(?!-?raw)/i => '"euc-cn"' );
       # for Encode::JP
       define_alias( qr/\bjis$/i            => '"7bit-jis"' );
       define_alias( qr/\beuc.*jp$/i        => '"euc-jp"' );
       define_alias( qr/\bjp.*euc$/i        => '"euc-jp"' );
       define_alias( qr/\bujis$/i           => '"euc-jp"' );
       define_alias( qr/\bshift.*jis$/i     => '"shiftjis"' );
       define_alias( qr/\bsjis$/i           => '"shiftjis"' );
       define_alias( qr/\bwindows-31j$/i    => '"cp932"' );
       # for Encode::KR
       define_alias( qr/\beuc.*kr$/i        => '"euc-kr"' );
       define_alias( qr/\bkr.*euc$/i        => '"euc-kr"' );
       # This fixes ksc5601 vs. euc-kr confusion, practically
       define_alias( qr/(?:x-)?uhc$/i            => '"cp949"' );
       define_alias( qr/(?:x-)?windows-949$/i    => '"cp949"' );
       define_alias( qr/\bks_c_5601-1987$/i      => '"cp949"' );
       # for Encode::TW
       define_alias( qr/\bbig-?5$/i              => '"big5-eten"' );
       define_alias( qr/\bbig5-?et(?:en)?$/i     => '"big5-eten"' );
       define_alias( qr/\btca[-_]?big5$/i        => '"big5-eten"' );
       define_alias( qr/\bbig5-?hk(?:scs)?$/i    => '"big5-hkscs"' );
       define_alias( qr/\bhk(?:scs)?[-_]?big5$/i  => '"big5-hkscs"' );
   }
   # utf8 is blessed :)
   define_alias( qr/^UTF-8$/i => '"utf-8-strict"');
   # At last, Map white space and _ to '-'
   define_alias( qr/^(\S+)[\s_]+(.*)$/i => '"$1-$2"' );
}

1;
__END__

# TODO: HP-UX '8' encodings arabic8 greek8 hebrew8 kana8 thai8 turkish8
# TODO: HP-UX '15' encodings japanese15 korean15 roi15
# TODO: Cyrillic encoding ISO-IR-111 (useful?)
# TODO: Armenian encoding ARMSCII-8
# TODO: Hebrew encoding ISO-8859-8-1
# TODO: Thai encoding TCVN
# TODO: Vietnamese encodings VPS
# TODO: Mac Asian+African encodings: Arabic Armenian Bengali Burmese
#       ChineseSimp ChineseTrad Devanagari Ethiopic ExtArabic
#       Farsi Georgian Gujarati Gurmukhi Hebrew Japanese
#       Kannada Khmer Korean Laotian Malayalam Mongolian
#       Oriya Sinhalese Symbol Tamil Telugu Tibetan Vietnamese

=head1 NAME

Encode::Alias - alias definitions to encodings

=head1 SYNOPSIS

 use Encode;
 use Encode::Alias;
 define_alias( newName => ENCODING);

=head1 DESCRIPTION

Allows newName to be used as an alias for ENCODING. ENCODING may be
either the name of an encoding or an encoding object (as described 
in L<Encode>).

Currently I<newName> can be specified in the following ways:

=over 4

=item As a simple string.

=item As a qr// compiled regular expression, e.g.:

 define_alias( qr/^iso8859-(\d+)$/i => '"iso-8859-$1"' );

In this case, if I<ENCODING> is not a reference, it is C<eval>-ed
in order to allow C<$1> etc. to be substituted.  The example is one
way to alias names as used in X11 fonts to the MIME names for the
iso-8859-* family.  Note the double quotes inside the single quotes.

(or, you don't have to do this yourself because this example is predefined)

If you are using a regex here, you have to use the quotes as shown or
it won't work.  Also note that regex handling is tricky even for the
experienced.  Use this feature with caution.

=item As a code reference, e.g.:

 define_alias( sub {shift =~ /^iso8859-(\d+)$/i ? "iso-8859-$1" : undef } );

The same effect as the example above in a different way.  The coderef
takes the alias name as an argument and returns a canonical name on
success or undef if not.  Note the second argument is not required.
Use this with even more caution than the regex version.

=back

=head3 Changes in code reference aliasing

As of Encode 1.87, the older form

 define_alias( sub { return  /^iso8859-(\d+)$/i ? "iso-8859-$1" : undef } );

no longer works. 

Encode up to 1.86 internally used "local $_" to implement ths older
form.  But consider the code below;

 use Encode;
 $_ = "eeeee" ;
 while (/(e)/g) {
   my $utf = decode('aliased-encoding-name', $1);
   print "position:",pos,"\n";
 }

Prior to Encode 1.86 this fails because of "local $_".

=head2 Alias overloading

You can override predefined aliases by simply applying define_alias().
The new alias is always evaluated first, and when necessary,
define_alias() flushes the internal cache to make the new definition
available.

 # redirect SHIFT_JIS to MS/IBM Code Page 932, which is a
 # superset of SHIFT_JIS

 define_alias( qr/shift.*jis$/i  => '"cp932"' );
 define_alias( qr/sjis$/i        => '"cp932"' );

If you want to zap all predefined aliases, you can use

 Encode::Alias->undef_aliases;

to do so.  And

 Encode::Alias->init_aliases;

gets the factory settings back.

=head1 SEE ALSO

L<Encode>, L<Encode::Supported>

=cut